Reading this made it clear that while the author definitely did some research and came to understand some aspects of magic, there was a lot she was woefully ignorant of. Perhaps what was most telling was the attitude she had toward the subject and toward the people she observed, a subtle attitude that demonstrated a lack of respect. For her magic, seemed liked an opportunity to find a subject study it, write about it, and then promptly leave without continuing further work or further engaging the subject and testing her analysis. She apparently only did this study for a year.
Poor research methodology, including mis-representing herself and failure to acquire adequate background information on the subject. This is a highly approved text, often used in college level anthropology courses.